Safety lock



.1.` c. GooDsoN SAFETY LOCK Filed Jan. 22, 1945 www .falllezf lamfala,

Sept., 2, 1947.

Patente'cl Sept. Z, 1947 UNITED OFFICE 3 Claims.

This invention relates to a safety lock of the belt and chain. type for securing a door in a partially open position, and has to do particularly with the construction ofu the retainer for the locking member.

Heretofore, the standard type of bolt and chain lock has usually includedv a member for attachment to the door casing, a chain including a lock member extending therefrom, and a retainer member mounted on the interior surface of the door adjacent the door casing and provided with a horizontally positioned key slot. This type of construction was designed to permit the door to be partially opened Without unlocking to allow the insertion of packages, newspapers and the like. It Will be appreciated that in this construction the permissible length of the chain is severely restricted because of the ease with which the h'and could otherwise be inserted in the door to remove the locking member from the slot. As a result, only packages of smally size can be inserted.

Moreover, even though a chain olf restricted length is employed, the locking means may be easily removed from the slot by insertion into the door opening of a piece of medium weight cardboard, a little more than double the length of the chain track. In this operation, the cardboard is bent at a point slightly longer than the track and a shallow notch cut in the end so that it will not slip off the locking means. This end is then placed against the locking means between the chain and the retainer member from above and held in place from the outside. If the cardboard is slipped down to a horizontal position as the door is pulled shut, the locking member is forced to slide down the slot and through the opening provided for its removal.

Attempts have been made to give additional protection by providing the retaining member with a series of members designed to impede the removal of the locking means. However, these devices have proved to be difficult to operate and expensive to manufacture.

One of the objects of the present invention is to avoid the disadvantages 0f the prior art.

Anotherobject of the present invention is to provide a retainer member, for a safety lock of the bolt and chain type, which comprises a track laterally divided into two portions, one portion of which can be positioned in such a manner that the lock member cannot be removed from, the track from the outside of the door.

With these and other objects in view which will be apparent from the subsequent description, the present invention relates broadly to a safety lock lil of the bolt and chain type, for securing a door in a partially open position, in which the retainer for the locking member comprises a track laterally divided into two portions, one portion of th'e track being constructed so that it can be positioned to obstruct removal of the locking member from the remaining portion of the track. This type of construction permits the use of a longer iiexible member than can be employed on present standard equipment because the locking member cannot be removed from the track by manipulation from outside of the door.

In the drawings:

Figure 1 is a fragmentary plan view of a doer and casing equipped with a safety lock, of the bolt and chain type, embodying the present invention.

Figure 2 is a View taken along the line 2-2 of Figure 1.

Figure 3 is a view taken along the line 3--3 of Figure 1.

In the embodiment disclosed in the drawings, for purposes of illustration, the safety lock comprises a retainer member I and an attachment plate 2 mounted respectively on a conventional door 3 and a door casing Il. The retainer member I and the attachment plate 2 are connected by a chain member 5 to the end of which is attached a locking member The chain 5 is fastened to the attachment plate 2 in any suitable manner, such as the bracket 8 which is an eXtension of a. portion I which is designed to carry the locking member when th'e device is not in use.

The retainer member I may be in the form of a plate which is securely fastened to thel door and upon which is mounted a horizontally eX- tending track. As best shown in Figure l, this track is laterally divided to form a pivotally mounted portion 9 and a rigidly mounted portion IIJ.

As sh-own in Figures 2 and 3, both portions of the track may be made of a piece of sheet metal a double thickness of which is pressed to form a channel, th'e walls of which terminate in flanged shoulders. The track portion 9 is pivotally mounted on a bolt I I which extends through the plate I. As best shown in Figure 2, the eX- tremities of the sheet metal forming the track I0 extend through a slot l2 in the plate I and are flanged as shown at I3. The flanges rigidly secure this portion of the track to the plate I.

In the preferred construction, the bolt I I is ofiset from the center of the track portion 9 so that the force of gravity will cause the two portions of the track to be normally out of alignment. In the illustrated construction, the bolt l I is offset towards the fixed portion of the track IU. However, the bolt Il could be centrally positioned and the portion 9 could be angularly positioned with respect to the remaining portion l by manual operation.

For ecient operation the track portion 9 should be at least one and one-quarter inches long and the track portion l0 at least twice that length. The inner end of the track portion lll must, of course, be closed to form a stop for the locking member 6. The center section of the joint between the track portions 9 and i0 is preferably cut away to permit free movement, and the bottom edge of the joint on the track portion 9 and the top edge of the joint on track portion l0 are cut to overlap the adjacent portions of the track I secured to the door plate, and means to pivotally to prevent the track portion 9` from pivoting to a completely vertical position. All contacting joints of the transverse cut are beveled to form a perfect joint when the track portions are aligned,

As shown in Figure 2, the lock member 6 may be in the form of a slide bracket having turned edges lll which are adapted to engage the flanged shoulders of the track portions 9 and lil. The slide brackets 6 may be secured` to the chain 5 in any suitable manner as, for example, by a bolt l5. In operation, after the track portions 9 and l0 h-ave been aligned, the slide bracket 6 is placed in engagement with the track portion 9 and is moved along this member in interengagement with the fixed track portion lll. The track portion S is then allowed to pivot about its axis I l to a position in angular relationship to the track portion lo. In this position the slide bracket 6 cannot then be removed until the track portions 9 and i@ are again aligned. This cannot be accomplished except from the inside of the door.

While for purposes of illustration one form of the invention has been disclosed, it is believed obvious that various changes may be made in the track and connecting structure without departing from the spirit of the invention. It will also be appreciated that in certain types of Ydoor construction the retainer member l' could be positioned on the casing rather than upon the door and could be mounted vertically instead of horizontally in the manner shown in the drawings.

I claim: 1. A safety lock of the bolt and chain type to prevent a door from being completely opened comprising a plate for attachment to a door casing adjacent the center portion of the swingable edge of the door, a slide bracket, a chain connecting the slide bracket to the plate, a retainer plate secured to the door adjacent the rst mentioned plate, a track for receiving the slide bracket mounted horizontally on the retainer plate, said track being laterally divided into two portions, the portion of the track nearest the door casing being rigidly secured to the retainer plate, and means to pivotally mount the remaining track portion on the Vretainer plate, the pivot being offset from the center of this track portion toward the stationary portion of the track to cause the two portions of the track to be normally out of alignment, thereby preventing the slide bracket from being removed from the stationary portion of the track until the two portions of the track are aligned by movement of the pivoted portion to a horizontal position.

2. A safety lock of the bolt and chain type to prevent a door from being completely opened comprising a plate for attachment to a door casing adjacent the center portion of the swingable edge of the door, a slide bracket, a chain connecting the slide bracket to the plate, a retainer plate secured to the door adjacent the i'lrst mentioned plate, a flanged channel member to form a track for receiving the slide bracket mounted horizontally on the retainer plate, said track being laterally divided into two portions, the portion of the track nearest the door casing being rigidly mount the remaining track portion on the retainer plate, the pivot being offset from the center of this track portion to cause the two portions of the track to be normally out of alignment thereby preventing the slide bracket from being removed from the stationary portion of the track until the two portions of the track are aligned by movement of the pivoted portion to a horizontal position.

3. In a safety lock of the bolt and chain type in which a plate fastened to a door casing supports a chain to which is attached a bracket for locking cooperation with a retainer member mounted on the door so as to lock the door from being opened more than a predetermined amount when the bracket is positioned on the retainer member, a retainer member comprising a plate secured to the door and supporting a track -on which the bracket slides, said track including two portions, one of which is fxedly mounted on the plate and the other is pivotally mounted thereon, the pivot for the pivotally mounted portion being offset from its center toward the xed portion of the track, said track having its sides raised from the plate as flanges, the adjacent surfaces of said flanges of said pivoted and fixed portions being cut on a slant so as to register with each other when the pivoted portion is aligned with the fixed portion and so as to lock said bracket on the xed portion when the pivoted portion is not in alignment with the iixed portion, said pivoted portion being normally placed out of alignment with said xed portion by gravity.

JAMES C. GOODSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,777,146` McGlaughlin Sept. 30, 1930 2,003,473 Schulz et al J'une 4, 1935 2,076,605 West Apr. 13, 1937 376,813 Cleveland Jan.Y 24, 1888 467,165 Grandeman Jan. 19, 1892 2,887,755 Dayton July 20, 1937 FOREIGN PATENTS Number Country Date 3,442 Great Britain 1877 

